2 files changed, 67 insertions, 0 deletions

diff --git a/recipes-core/openjdk/openjdk-7-03b21/icedtea-jdk-powerpc-atomic64.patch b/recipes-core/openjdk/openjdk-7-03b21/icedtea-jdk-powerpc-atomic64.patch
new file mode 100644
index 0000000..cc5e4e8
--- /dev/null
+++ b/recipes-core/openjdk/openjdk-7-03b21/icedtea-jdk-powerpc-atomic64.patch
@@ -0,0 +1,65 @@
+http://mail.openjdk.java.net/pipermail/zero-dev/2010-June/000346.html
+
+this cute C code does the same thing on powerpc as the assembly code that
+was here before. If the compiler was built with the SPE extensions instead
+of traditional FPU and double operations are performed in HW then we are
+one step further: The compiler turns this into evldd & evstdd. Voila :)
+
+This C code could also be activated on s390. The compiler turns this into
+a single mvc instruction which does the copy operation. I don't know if
+mvc's copy ability is atomic _or_ not and therefore I leave it as it.
+
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
+
+./openjdk-src-dir/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.hpp
+Index: openjdk/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.hpp
+===================================================================
+--- openjdk/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.hpp.org      2011-11-14 14:07:32.000000000 -0800
++++ openjdk/hotspot/src/os_cpu/linux_zero/vm/os_linux_zero.hpp  2012-07-19 07:28:26.208405923 -0700
+@@ -25,6 +25,16 @@
+ 
+ #ifndef OS_CPU_LINUX_ZERO_VM_OS_LINUX_ZERO_HPP
+ #define OS_CPU_LINUX_ZERO_VM_OS_LINUX_ZERO_HPP
++#if defined(PPC) && !defined(_LP64)
++
++#ifndef __NO_FPRS__
++#define ATOMIC64_COPY_THROUGH_DOUBLE 1
++
++#elif defined(__SPE__) && !defined(_SOFT_DOUBLE)
++#define ATOMIC64_COPY_THROUGH_DOUBLE 1
++
++#endif
++#endif
+ 
+   static void setup_fpu() {}
+ 
+@@ -36,12 +46,23 @@
+ 
+   // Atomically copy 64 bits of data
+   static void atomic_copy64(volatile void *src, volatile void *dst) {
+-#if defined(PPC) && !defined(_LP64)
+-    double tmp;
+-    asm volatile ("lfd  %0, 0(%1)\n"
+-                  "stfd %0, 0(%2)\n"
+-                  : "=f"(tmp)
+-                  : "b"(src), "b"(dst));
++#if ATOMIC64_COPY_THROUGH_DOUBLE
++  /*
++   * In order to copy 8 bytes atomicly we rely on the trick that some
++   * architectures can load and store a double as a single operation.
++   * gcc picks the correct opcode here and with optimization turned on
++   * all temporary assignments are gone.                       - bigeasy
++   */
++   union {
++          double *d;
++          volatile void *v;
++   } s, d;
++
++   s.v = src;
++   d.v = dst;
++
++   *d.d = *s.d;
++
+ #elif defined(S390) && !defined(_LP64)
+     double tmp;
+     asm volatile ("ld  %0, 0(%1)\n"
diff --git a/recipes-core/openjdk/openjdk-7-release-03b21.inc b/recipes-core/openjdk/openjdk-7-release-03b21.inc
index 40c1cf6..2038e07 100644
--- a/recipes-core/openjdk/openjdk-7-release-03b21.inc
+++ b/recipes-core/openjdk/openjdk-7-release-03b21.inc
@@ -96,6 +96,7 @@ ICEDTEAPATCHES = "\
 ICEDTEAPATCHES_append_powerpc = " \
         file://icedtea-jdk-nio-use-host-cc.patch;apply=no \
         file://icedtea-jdk-ppc64-jvm-cfg.patch;apply=no \
+        file://icedtea-jdk-powerpc-atomic64.patch;apply=no \
         "
 ICEDTEAPATCHES_append_powerpc64 = " \
         file://icedtea-jdk-nio-use-host-cc.patch;apply=no \
@@ -139,6 +140,7 @@ DISTRIBUTION_PATCHES_append_libc-uclibc = "\
 DISTRIBUTION_PATCHES_append_powerpc = " \
         patches/icedtea-jdk-nio-use-host-cc.patch \
         patches/icedtea-jdk-ppc64-jvm-cfg.patch \
+        patches/icedtea-jdk-powerpc-atomic64.patch \
         "
 DISTRIBUTION_PATCHES_append_powerpc64 = " \
         patches/icedtea-jdk-nio-use-host-cc.patch \